We sing about it, we write about it, we just plain desire it.

Some even think we can find it by watching TV. Next to the meaning of life, we most want to know how to be happy.

Tonight at 10 (!) on UNC-TV, PBS begins a three-part documentary exploring happiness called "This Emotional Life."

(Each episode is two hours long, so you might want to set the DVR.)

Hosted by Harvard professor Daniel Gilbert, the documentary examines why happiness is so elusive, using a mix of science and personal stories.

We learn the brain science behind different facets of happiness.

For my money, the funniest moment in NBC's two-hour comedy block last night came during Pierce's (Chevy Chase) college rock band debut, playing keyboards and singing backup to Vaughn's woeful song of heartbreak (and moving on), "Gettin' Rid of Britta."

The lyrics are clever, and Vaughn is easy on the eyes in that sensitive musician kind of way. Rocker Vaughn won me over with lines like, "It isn't like I would ever hit her, but I would sell her to the highest bidder." But it's Chevy chiming in with "she's a no good B" and "she's a G D B" while jamming on the keyboards that had me cracking up -- and watching over and over and over again.

Check it out below.

NBC's newest sitcom, "Community," has some big names and a lot of well-deserved buzz. Joel McHale, the popular host of E!'s "The Soup," is undoubtedly the star of the show, but "Community" also features a beloved comedy legend who is ripe for a comeback: Chevy Chase.

McHale (above with Danny Pudi) plays Jeff, an attorney whose undergraduate degree from Columbia (the country, not the school) is deemed illegitimate, so he must get a new degree in order to resume practicing law.

But of course, being the amoral jerk that he is, he tries to cheat his way through with the aid of a former client and psych professor played by Jon Oliver of "The Daily Show" (who thankfully, is only in the pilot).